There is provided mechanisms for determining frequency location of a primary cell (PCell) for a wireless device in a carrier aggregation supported communications network having access to a group of low frequency bands and a group of high frequency bands. A method is performed by a network node. The method comprises acquiring an uplink load level for the group of low frequency bands. The method comprises acquiring a pathloss level between a wireless device served by the communications network and the network node. The method comprises selecting, from the acquired uplink load level and pathloss level, which one of the group of low frequency bands and the group of high frequency bands to place the frequency location of the PCell for the wireless device.